#include <iostream>
#include <iomanip>
using namespace std;

int main()
{
    int a, b, c;
    while(cin >> a >> b >> c)
    {
        if(a==0 && b==0 && c==0) break;

        cout << fixed << setprecision(c) << (long double)a/b << endl;

    }
    return 0;
}
